Department of Materials Processing, Graduate School of Engineering, Tohoku University.
Removable Partial Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.
Dent Mater J. 2020 Mar 31;39(2):256-261. doi: 10.4012/dmj.2018-426. Epub 2019 Nov 13.
The artifact volume generated in magnetic resonance (MR) images was quantitatively evaluated to investigate how artifact behavior correlates to the magnetic susceptibility and volume of an implanted metal device. For this, a new low-magnetic-susceptibility Zr-14Nb alloy was compared with two conventional dental alloys, Ti-6Al-7Nb alloy and Co-Cr-Mo alloy, using spherical specimens of each alloy prepared with four different diameters. Then, MR images were recorded under fast spin echo and gradient echo conditions, from which the artifact volume was measured. The artifact volume decreased with the magnetic susceptibility, volume, and mass of the specimens, and significant linear correlations were observed. The artifact volume can be estimated by the equations presented here; nevertheless, further studies are necessary to interpret the influence of some important factors (e.g., imaging conditions, shape, and orientation) to predict the artifact volume more precisely.
对磁共振（MR）图像中的伪影体积进行定量评估，以研究伪影行为与植入金属装置的磁导率和体积之间的关系。为此，使用每个合金的四个不同直径制备的球形试样，比较了新型低磁导率 Zr-14Nb 合金与两种传统牙科合金 Ti-6Al-7Nb 合金和 Co-Cr-Mo 合金。然后，在快速自旋回波和梯度回波条件下记录 MR 图像，从这些图像中测量伪影体积。随着试样的磁导率、体积和质量的增加，伪影体积减小，并且观察到显著的线性相关性。可以通过这里给出的方程来估算伪影体积；然而，需要进一步的研究来解释一些重要因素（例如，成像条件、形状和方向）的影响，以便更准确地预测伪影体积。
